1. Field of the Invention
The present invention relates to liquid crystal display technology, and more particularly, to a auto-stereoscopic display device, a liquid crystal lens, and a driving method thereof.
2. Description of the Prior Art
With the maturity in LCD technology, the auto-stereoscopic display technologies are also vigorously developed. Nowadays, there are two types of auto-stereoscopic display technologies in general, stereoscopic display technology and auto-stereoscopic display technology. A user of a stereoscopic display has to wear special type glasses to see the three-dimensional images. Not only does the user spend money on the special type glasses, but also the user does not feel comfortable when wearing them. The requirement of wearing such special type glasses impedes the widespread utilization of auto-stereoscopic displays. As for a user of an auto-stereoscopic display, he/she can see three-dimension images without the assistance of any extra devices so as to get rid of the requirement of wearing the special type glasses. Hence, auto-stereoscopic displays enjoy more popularity than auto-stereoscopic displays among the users and the sellers.
A commonly seen auto-stereoscopic display utilizes slanted lenticular lenses to realize three-dimensional display. Since the lenticular lenses will not block light from the backlight, the brightness uniformity is improved. A better display effect is thus achieved.
A liquid crystal lens is used for forming a slant lenticular lens in the conventional technology so that both of 2D (two-dimensional) and 3D (three-dimensional) images can be displayed on a auto-stereoscopic display device. A plurality of slant lenticular lenses 12 are formed on a panel 11, as shown in FIG. 1. Images that the left eye needs are refracted to the left eye through the plurality of slant lenticular lenses 12, and images that the right eye needs are refracted to the right eye through the plurality of slant lenticular lenses 12. In this way, 3D images are shown. In the 3D display mode, the liquid crystal lens in the auto-stereoscopic display device works, while in the 2D display mode, the liquid crystal lens works as a flat mirror does. The light has to pass through the panel 11 and the liquid crystal lens before being emitted. It means that the light will be deteriorated to a degree, causing the brightness and luminance of the 2D display mode to be degraded.